Electrical interconnection devices incorporating redundant contact points for reducing capacitive stubs and improved signal integrity

ABSTRACT

An electrical interconnection device for establishing redundant contacts between the ends of two conductive elements to be mated, creating a electrical interconnection without capacitive stubs.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from, and hereby incorporates byreference in their entirety and for all purposes, U.S. ProvisionalApplication No. 60/557,127, filed Mar. 26, 2004, entitled: “CurvedCantilever Beam Spring Contacts Integrated Into Interconnection DevicesFor Improved Signal Integrity,” U.S. Provisional Application No.60/624,519, filed Nov. 1, 2004, entitled: “Curved Cantilever Beam SpringContacts Integrated Into Interconnection Devices For Improved SignalIntegrity II,” and U.S. patent application Ser. No. 11/093,266 filedMar. 28, 2005 and entitled “Electrical Interconnection Devicesincorporating Redundant Contact Points for Reducing Capacitive Stubs andImproved Signal Integrity” by Yasumura et al.

TECHNICAL FIELD

The disclosed embodiments relate generally to the field of electricalinterconnections. More particularly, the disclosed embodiments relate toelectrical interconnection devices having redundant electrical contactgeometries that eliminate capacitive stubs.

BACKGROUND

Electronic systems often utilize discrete electrical components thatmust be connected together using structures and devices that establishelectrical and mechanical contact. Electrical signals enter, traverseand exit these electromechanical connection structures, which oftenrepresent the site of significant signal degradation due to attenuation,reflection, interference or skew, any of which contribute to signaldegradation that may harm the performance of the system. Systemarchitects can maintain signal integrity by utilizing connection devicesthat wherever possible lower inductance, reduce parasitic capacitance,minimize signal distortion and reflections, eliminate skew, and matchimpedance. In addition, system architects can improve signal integrityby utilizing electrical connection structures that optimizeelectromechanical contact force and contact wipe.

Vias, or plated through holes, in printed circuit boards are structurescommonly used to establish electromechanical connections betweenelectrical components and printed circuit boards. Vias can causesignificant harm to signal integrity. FIG. 1 illustrates a prior-artelectrical connector system in which the electrical connector 101attaches to a printed circuit board 102, where the printed circuit boardcontains multiple layers 103. A conductive pin 104 is inserted into aplated through hole 105 (which consists of a hole 106, drilled throughthe printed circuit board, and an annular pad 107—both of which areplated with a conductive material). In this illustration, the platedthrough holes create anchor points for the electrical connector, and theplated through hole makes an electrical connection between theconductive pin 104 and a trace 108 that may be located on the surface ofthe printed circuit board one or more layers within the printed circuitboard. Many of the structures associated with vias incorporatecapacitive stubs 105, 106, 107, which degrade signal integrity.

FIG. 2 illustrates prior art showing a typical electromechanical contactassembly comprising a post 201 inserted into a tuning fork receptacle202. The structure of this assembly may have unwanted parasiticcapacitances resulting from three elements: (1) the capacitive stubformed by the portion of post 203 that extends into the assembly beyondthe electrical contact points 204; (2) the capacitive stubs formed bythe two projections 205 that extend away from the assembly beyond thecontact points 204; and (3) the 90 degree folds 206 in the tuning forkreceptacle 202.

FIG. 2A illustrates a prior art electrical connection device wherein theelectrical conductor 207, makes contact with an electrical contact pad208 at the electrical contact point 210, which moves along theelectrical contact pad 208 as force is applied to the electricalconductor 207, causing a wiping motion 211 known as “contact wipe”,which clears corrosion from the electrical contact pad 208 and improvesthe electrical connection at the electrical contact point 210. After thecontact wiping motion is complete and the electrical interconnection hasbeen established, the electrical contact pad 208 has a capacitive stub209 to the right of the electrical interconnection point 210. The stubcauses parasitic capacitance.

FIG. 3A illustrates an isometric view and an oblique side view of acommon prior art electromechanical contact assembly comprising twoelectrical conductors 305, 306 to be brought together an mated,electrical conductor 305 having a conductive protrusion 307 is alignedtoward the counterpart conductor 306. Conductive protrusion 307 focusesthe force pressing conductive elements 305 and 306 together, creating amore focused area of contact. The advantage of adding a protrusion isthat reducing the area where the contact force is brought to bearincreases the force per unit of area at the point of contact, betterovercoming corrosion and small imperfections on the surfaces of theconductive elements, both of which can cause signal degradation and cangenerate heat. The conductive protrusion 307 also creates capacitivestubs 308, 309, at the end of conductive elements 305 and 306, whichcapacitive stubs create parasitic capacitance that contributes to signaldegradation.

Despite these and other efforts in the art, further improvement in costand performance is possible by introducing novel elements, simplifyingdesign and lowering manufacturing cost.

BRIEF DESCRIPTION OF DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1 illustrates a fundamental prior art structure for use inconstructing electrical connectors and assembling them to printedcircuit boards using a plated through hole;

FIG. 2 illustrates a prior art electrical connector in which a post isinserted into a tuning fork type receptacle;

FIG. 2A illustrates a prior art electrical connector in which theelectrical contact between a conductive element and a contact padcreates a capacitive stub;

FIG. 3 illustrates a printed circuit board having a stair step structureto which embodiments of the invention can connect;

FIG. 3A illustrates a prior art electrical connector in which a narrowflat conductive element with a protrusion is mated with a narrow flatconductive element.

FIG. 4 illustrates an embodiment comprising two conductive elements,each conductive element with a conductive structure at its end disposedto make contact with the body of the counterpart conductive element;

FIG. 5 illustrates an embodiment comprising two conductive elementsmounted to a non-flexible structure, the end of each conductive elementbeing comprised of a curved resilient conductive structure;

FIG. 6 illustrates an embodiment, in which a conductive element ismounted to a non-flexible structure and has a curved flexible end thatis disposed to connect to the body of a counterpart conductive element;

FIG. 7 illustrates an embodiment incorporating a curved conductiveelement that is tapered from the attachment area to the electricalcontact point;

FIG. 8 illustrates an embodiment incorporating two tapered curvedconductive elements surrounded by angled walls at their attachment pointand cavities for accommodating the angled walls on the opposing likeassembly;

FIG. 9 illustrates an embodiment of a signal trace that is etched fromconductive sheet material with adhesive film removed from beneath thetrace's end portions and the ends curved upward to create curvedconductive elements;

FIG. 10 illustrates the substrate disposed under an array of the curvedconductive elements in FIG. 8 that incorporates angled walls and thecorresponding cavity;

FIG. 11 illustrates an embodiment, multiple curved conductive elements,tied together into one entity by connecting bars, attached to thesubstrate in FIG. 10;

FIG. 12 illustrates the multiple curved conductive elements from FIG. 11with the connecting bars removed;

FIG. 13 illustrates the assembly from FIG. 12 assembled to a circuitstructure upon which the ends of the curved conductive elements areconductively attached to the conductive signal traces on the circuitstructure;

FIG. 14A illustrates a side view of the embodiment, two curvedconductive elements from FIG. 5 as they begin to contact each other;

FIG. 14B is a continuation in time of the conductors from FIG. 14Ashowing how the curved conductive elements move toward each other topartially flatten them against the underlying substrate;

FIG. 14C illustrates the curved conductive elements when they have fullymoved against each other and the beams are fully flattened against theunderlying substrates;

FIG. 15A shows a side view of an embodiment, a curved conductive elementattached to a substrate;

FIG. 15B illustrates the curved conductive element's properties in FIG.15A when a force F1 is applied;

FIG. 15C shows the curved conductive element in FIG. 15A except that aportion of the substrate is removed;

FIG. 15D illustrates the curved conductive element's properties in FIG.15C when a force F2 is applied;

FIG. 16 illustrates how the absence of one of the curved conductiveelements, which has been replaced by a conductive pad, creates acapacitive stub;

FIG. 17 illustrates an embodiment wherein shock forces (F) affect theelectrical continuity through the curved conductive elements;

FIG. 18 illustrates an embodiment, an electrical connector using thecurved conductive elements in a multiple-layered flexible circuit thatis disposed at 90 degrees;

FIG. 19 illustrates a close up of the embodiment, curved conductiveelements comprising ground, differential signal, ground, differentialsignal, and ground rows in FIG. 18;

FIG. 20 illustrates an embodiment, curved conductive elements on themating electrical component, in this case, a printed circuit board;

FIG. 21 illustrates a cross section through the embodiment, theelectrical connector and printed circuit board shown in FIGS. 19 and 20respectively just as the electrical contacts come together;

FIG. 22 illustrates an embodiment where the electromechanicalconnections are made on surfaces of electrical components arranged in astairstep manner;

FIG. 23 illustrates a cross section through an embodiment, an electricalconnector composed of rows of conductors in multiple layers that havethe centers of its conductors disposed at an angle to allow the signalsto have the shortest path through the electrical connector betweenelectrical components arranged at an angle to each other;

FIG. 24 illustrates an embodiment, in which curved conductive elementsare disposed at the end of a flexible circuit with a clamp at the end ofthe circuit providing contact force;

FIG. 25 illustrates an embodiment in a multiple-branched cable, whoseends are configured as in FIG. 24, that is connected to electricalcontact surfaces arranged in a stair step configuration on a backplane,as in FIG. 20, that is also connected to an integrated packageincorporating the same stair step electrical contact configuration as inFIG. 20;

FIG. 26 illustrates an exploded view of the assembly in FIG. 25;

FIG. 27 illustrates an embodiment wherein the electrical components tobe connected are disposed at 180 degrees or some other angle to eachother and at a distance from each other;

FIG. 28 illustrates an embodiment wherein the curved conductive elementsare an extension of a flexible circuit's etched signal traces, cablewires or conductors in a coaxial cable;

FIG. 29 illustrates an embodiment wherein the curved conductive elementsare disposed in a stair step structure so that the electricalcomponents' curved conductive elements are opposite each other;

FIG. 30 shows an embodiment wherein the curved conductive elements areat an angle with respect to the surfaces of the electrical components.

FIGS. 31 and 32 illustrate methods for bending the curved conductiveelement into a curved shape;

FIG. 33 shows an isometric view of an embodiment wherein a pivotingconductive element is enclosed in an insulative mating post;

FIG. 34 illustrates the structure of the pivoting conductive element inFIG. 33;

FIG. 35 illustrates the various features of the embodiment and thepivoting conductive element in FIG. 33;

FIG. 36 is a sectioned view of the features in the mating post shown inFIG. 33;

FIG. 37 is sectioned view of FIG. 33 showing the pivoting conductiveelement assembled into the mating post;

FIGS. 38A, 38B, and 38C illustrate the different positions of thepivoting conductive elements and the post assemblies in FIG. 33 as theymate;

FIG. 39 illustrates an embodiment, an electrical connector composed ofarrays of the pivoting conductive elements and post assemblies shown inFIG. 33;

FIG. 40 illustrates an embodiment, the pivoting conductive elements andpost assemblies shown in FIG. 33 staggered vertically so that thesurface mount solder tails conform to the stair step surfaces on theelectrical component to be connected;

FIG. 41 illustrates an embodiment, a post assembly enclosing a straightconductive element (not shown) and a post assembly having an inlineconductive element;

FIG. 42 illustrates a sectioned view of the assemblies shown in FIG. 41;

FIGS. 43A, 43B illustrates the mating action of the post assemblies inFIG. 42;

FIG. 44 illustrates an embodiment of an electrical assembly comprised ofa paralleled conductive element and a signal trace;

FIG. 45A illustrates the electrical assembly in FIG. 44 just as itselectrical contacts touch;

FIG. 45B illustrates the electrical assembly in FIG. 44 after the signaltrace has mated with the paralleled conductive element;

FIG. 46 illustrates the electrical assembly in FIG. 44 with multiplepairs of signal traces and paralleled conductive elements embedded inchannels in the underlying substrate;

FIG. 47 illustrates a stair step version of the electrical assembly inFIG. 44;

FIG. 48 illustrates another embodiment, a signal or power bus withmultiple curved conductive elements on the bus;

FIG. 49 illustrates the signal or power bus in FIG. 48 with the bus'layers exploded apart;

FIG. 50 illustrates a section view of FIG. 49 showing the left side ofthe signal or power bus' conductor residing inside the cavity formedinside the PCB layers;

FIG. 51 illustrates an embodiment, curved conductive elements used atthe ends of center conductors in coaxial transmission line structures;

FIG. 52 illustrates the assembly in FIG. 51 without the top groundplane;

FIG. 53 illustrates an embodiment, a unshaped interposer conductor usingtwo curved conductive elements for use in an interposer connector;

FIG. 54 shows another embodiment of the unshaped interposer conductorshown in FIG. 53, a z-shaped interposer conductor that could also beused in an interposer connector;

FIG. 55 illustrates an embodiment showing an interposer connector havingan array of interposer conductors captured by a capture plate and anarray plate;

FIG. 56 illustrates an exploded view of FIG. 55;

FIG. 57 illustrates the interposer connector in FIG. 55 without thecapture plate;

FIG. 58 illustrates an embodiment, an interposer connector with rows ofalternating ground springs and signal springs in signal ground barassemblies;

FIG. 59 illustrates a signal ground bar assembly composed of signal andground springs using the curved conductive element concept;

FIG. 60 is an exploded view of the signal ground bar assemblyillustrated in FIG. 59;

FIG. 61 is a sectioned view through the signal ground bar assembly inFIG. 59;

FIG. 62 illustrates a signal ground bar assembly with a cavity in theinsulator for an extra ground plane;

FIG. 63 illustrates an embodiment with the electrical contact rows ondifferent stair step surfaces;

FIG. 64 illustrates another embodiment with the electrical contact rowson different stair step surfaces; and

FIG. 65 illustrates an embodiment of the curved conductive elements withmultiple electrical contact redundancy.

DETAILED DESCRIPTION

Embodiments of the invention disclosed herein include structures andmethods for making three dimensional interconnections between electricalcomponents. An electrical signal traversing the device will encounteronly electrically-mated, conductive elements that have no capacitivestubs or capacitive stubs so small as to be negligible in relation tothe circuit.

In the following description and in the accompanying drawings, specificterminology and drawing symbols are set forth to provide a thoroughunderstanding of the embodiments. In some instances, the terminology andsymbols may imply specific details that are not required to practiceembodiments of the invention. In the description of any embodiment, whenthe term electrical component is used, it may include but not be limitedto, printed circuit boards, connectors, cable ends, flexible circuitends, ceramic or silicon substrates, hybrid circuits, integratedcircuits, integrated circuit packages, electrical interposers, or acombination of them. Any of the aforementioned items may be substitutedfor any other aforementioned item. As an example, the term printedcircuit board may be interchanged with electrical component or flexiblecircuit. Printed circuit boards may be called PCBs or can besubcategorized as backplanes, mother boards, daughter boards, linecards, or daughter cards. In any embodiment of the invention, electricalcomponents may be shown or described at a 90 or 180 degree angle to eachother, but unless specifically stated otherwise can be at any otherangle.

The references to stair step electrical components made herein arereferences to electrical components that have contact surfaces in whichconductive planes and electrical signal traces are arranged in a stairstep configuration that allows connections to be established with otherconductive structures arranged in a stair step configuration. The stairstep connection surfaces allow electrical contact to be made withoutusing vias or plated through holes. Vias in electrical components, suchas printed circuit boards, are known to be a significant source ofsignal degradation. Stair step connection structures, and systems thatutilize stair step connection structures on one component mated to stairstep connectors, limit or eliminate the need for vias. Stair stepelectrical components described herein refer to, for example, any of thestair step printed circuit board structures disclosed in U.S. patentapplication Ser. No. 10/990,280 (“Stair Step Printed Circuit BoardStructures for High Speed Signal Transmissions”), filed Nov. 15, 2004,which is incorporated in its entirety herein by reference.

A number of the figures herein depict two conductors side by side thatcomprise a differential signal pair. In any embodiment, the conductorsmay be any conductive material such as metal-coated plastics, metal,conductive elastomers, conductive plastics or the like. In anyembodiment, or in any figure showing a conductor, the conductor may be adifferential pair, a single-ended conductor, single conductors, singleconductors in microwave and stripline geometries, or a coaxialconductor. In any figure showing a cross sectioned view of embodimentsof the invention, the presence of the cross section implies that thereare additional conductors behind and/or in front of the visibleconductors.

In any figure, although a conductor may appear to be at a specific anglewith respect to a printed circuit board's surface, it may be at anyangle with respect to a printed circuit board's surface.

Some of the figures show an embodiment that has one conductive elementwhich appears alone in the illustration. An embodiment may include theconductive element alone or arranged in rows or arrays of two or moresuch conductive elements.

Some of the figures show an embodiment that has one pair of conductiveelement that mate to create an electrical connection. An embodiment mayinclude one pair of such conductive elements alone or pairs of suchconductive elements arranged in rows arrays of two or more such pairs ofconductive elements.

In any figure, the conductive elements illustrated are part ofelectrical circuits. The conductive elements extend beyond the edge ofthe illustration and connect to wires, traces or other electricalstructures not pictured.

FIG. 3 illustrates prior art stair step electrical component structures,which exposes traces that run one or more layers within a multilayerelectrical component, such as a printed circuit board. The stair stepstructure provides a surface for establishing a point of connection withsuch traces without the use of plated through holes, also known as avias, which cause signal degradation. In FIG. 3, signal traces 304 thatrun in layers below the surface of the electrical component 301 areexposed by the stair step structure 302, 303 in which layers of theelectrical component above the signal trace are removed. The signaltraces may be exposed by a stair step structure 303 at the edge of theelectrical component or by a stair step structure disposed in a well 302away from the edge of the electrical component. One or more electricalcomponents that incorporate stair step structures may require stair stepelectrical connectors to establish electromechanical connections betweenelectrical components. The invention includes embodiments that functionwith stair step structures.

In any figure, a planar surface with electrical contact points may beinterchanged with a surface configured as a stair step. In any figure inwhich a conductive element is illustrated on a planar surface, theplanar surface may be one plane among two or more planar surfaces on theelectrical component, which planar surfaces are arranged in a stair stepconfiguration.

In any figure, a specific number of layers comprised of dielectricsheets, rows of conductors or conductive planes may be illustrated, butthis does not limit the number of layers that could be present inembodiments of the invention.

FIG. 4 is an isometric view and a oblique side view of an embodimentcomprising a pair of conductive elements 401, 402, shown in theirunmated state in the isometric view and in their mated state in theoblique view. In the embodiment, each conductive element 401, 402, has aconductive structure 403, 404 at its end disposed to make contact withthe body of the counterpart conductive element when the two conductiveelements are brought together. In the mated state, a space 403 betweenthe conductive structures 404, 403 exists where the conductive elements401, 402 are not in contact.

FIG. 5 is an isometric view of an embodiment comprising two counterpartconductive elements 500 that are to be mated to establish an electricalconnection. Each of the counterpart conductive elements 500 is mountedto a counterpart non-flexible structure 504, 505. The connectiveelements have curved resilient ends aligned to contact the landing zones502 of their counterpart conductive elements as the non-flexiblestructures 504, 505 are brought together. As the non-flexible structuresare drawn together, the tips 501 of each conductive element 500 makecontact with the landing zone 502 of the counterpart conductive element,leaving a space 503 between the points where each tip 501 touches itscounterpart landing area. The closer together non-conductive structures504 and 505 are drawn after initial contact between counterpartconductive elements 500, the further along the landing zones 502 thetips will move, resulting in contact wipe.

FIG. 6 is an isometric view of an embodiment comprising a conductiveelement with a landing zone 602, a curved resilient section 600, and atip 601 disposed so that the tip will make contact with a contact zoneof a counterpart conductive element. The non-curved portion of theconductive element is connected to a non-flexible structure 603, whichmay include but is not limited to a substrate. The tip of thecounterpart conductive element will make contact with the landing zone602 so that when mated, the tip 601 will be touching the landing zone ofthe counterpart conductive element and the tip of the counterpartconductive element will be touching the landing zone 602, creating twopoints of contact between the embodiment and the counterpart conductiveelement and a space where no contact exists. As the counterpartconductive elements are brought together, the contact points migrate,causing contact wipe.

FIG. 7 is another embodiment of the interconnection device in FIG. 6,showing a curved resilient end 700 to the conductive element. The curvedresilient end incorporates a more gradual taper starting at the width701 and tapering down in size as the contact zone 702 is approached. Thetaper can also vary in thickness in addition to width. The taper isincluded so that the stresses are more uniformly distributed over thelength of the conductive element. This lowers the maximum stress levelto diminish cyclic fatigue or permanent distortion.

FIG. 8 illustrates an underlying structure 800 configured with angledwalls 801 on either side of the landing zone 803 on the conductiveelement 806. The angled walls 801 guide the counterpart conductiveelement's tip 804 onto the electrical contact area 803 to promotealignment. The substrate includes a step 805 that accommodates theangled walls on the opposing substrate. The structures nest togetherallowing the conductive elements to bend flat or substantially flat topromote complete mating.

FIG. 9 illustrates an embodiment wherein a conductive signal trace 900may be etched, stamped or otherwise constructed from a spring-likematerial such as beryllium copper. The spring-like material in sheetform may be adhered, using an adhesive film 902, to a dielectricsubstrate 901 such as polyimide. At one end or at either end of theconductive signal trace 900, a portion of the trace may be released fromthe underlying dielectric substrate 901 by etching or removing anappropriate area 903 of adhesive layer 902. The released portion of thetrace can be bent by various methods into the required shape of aconductive element 904 and having the same properties of conductiveelement 500. from FIG. 5

FIG. 10 shows the substrate 1000, incorporating rows of angled guidewalls.

FIG. 11 through 13 shows an assembly incorporating rows of curvedtapered resilient conductive elements and angled guide walls. FIG. 11shows a row of conductive elements 1101 adhered to the underlyingsubstrate with angled guide walls 1000 shown in FIG. 10. There areintegral connecting bars 1103 connecting the conductive elements 1101together. The connecting bars 1103 have narrowed areas that act asbreakoff points 1104 so the connecting bars 1103 can be separated fromthe conductive elements 1101.

FIG. 12 shows the conductive elements 1101 on the substrate 1000 withoutthe connecting bars 1103. The shaded areas 1200 illustrate the surfaceswhere the connecting bars 1103 have been etched, sheared or broken awayfrom the conductive elements 1101.

FIG. 13 shows the assembly in FIG. 12 placed upon an electricalcomponent 1301 that includes traces 1303, to which the curved resilientconductive elements 1101 attach. The base 1302 of each conductiveelement aligns and makes contact with signal traces 1303 on the circuitstructure. The signal traces 1303 and the conductive elements 1101 areconductively attached to each other by means such as welding, solderingor laser welding, but not limited by such means.

FIGS. 14A through 14C illustrate how the free beam lengths shorten asthe conductive elements mate. FIG. 14A shows the embodiment wherein thecurved resilient ends of the conductive elements 1400, attached to theunderlying non-flexible structures 1402, are beginning to touch. Thefree beam lengths 1401 are at a maximum. The arrows show the directionof movement of the opposing non-flexible structures 1402, to which thecounterpart conductive elements 1400 are attached. FIG. 14B shows thenon-flexible structures 1402 moving toward each other and thecounterpart conductive elements 1400 partially flattening. The free beamlengths 1403 are at an intermediate length. FIG. 14C shows theconductive elements 1400 when they are fully mated. The conductiveelements 1406 have been substantially flattened against their respectiveunderlying substrates 1402. The free beam lengths 1404 are at a minimum.

The action described in the previous paragraph results in twoproperties, which will be explained in FIGS. 15A through 15C. Thecontact forces of two different conductive element configurations willbe compared to each other to show that the contact forces created areunequal. In FIG. 15A, the first configuration is of a conductive element1500 on an underlying substrate 1501 shown with no force applied to thetip via contact with a counterpart conductive element. In FIG. 15B,contact force F1 is applied to the tip. In FIG. 15C, the secondconfiguration has the same conductive element 1500 except that theunderlying non-flexible structure 1502 is absent under the free portionof the conductive element 1500. FIG. 15D illustrates the conductiveelement 1500 with a contact force F2 applied to the tip. It shows thesame amount of deflection as in FIG. 15B. The first property is that thecontact force F1 is greater than contact force F2 because the free beamlength of the conductive element 1500 in FIGS. 15A, 15B shortens whenmating occurs as was explained in FIGS. 14A through 14C. The secondproperty is that the stresses are distributed more uniformly over theconductive element's length in FIGS. 15A, 15B effectively lowering themaximum stresses. Thus, for the same spring properties, shape and size,the conductive element in FIGS. 15A, 15B has greater electrical contactreliability and is less susceptible to cyclic fatigue and permanentdeformation than the conductive element in FIGS. 15C, 15D because of thepresence of the underlying substrate 1501.

FIG. 16 illustrates how a capacitive stub 1601 is created to the left ofthe electrical contact point 1602 when there is a conductive element 500on one object and an electrical contact area 1603 on the other object.

FIG. 17 illustrates a third property of the embodiment that is itsincreased capability to withstand mechanical shock that may cause theconductive elements' electrical contact points to lift off itselectrical contact area thus causing signal interruption. The same shockforce F attempts to lift the top electrical contact point 1701 off thebottom electrical contact area 1702, but the same shock force F pressesthe bottom electrical contact point 1703 into the top electrical contactarea 1704 insuring that there is always electrical continuity.

FIG. 18 illustrates how the conductive elements 1801 are integrated intoan electrical connector 1800 whose conductive entities or signal tracesinterconnect two printed circuit boards (not shown) disposed at 90degrees or at any other angles to each other. The conductive entities orsignal traces may be etched into flexible circuit layers 1802, formedand assembled onto a connector body 1803 or they may be manufactured byany suitable method. FIG. 19 is a closeup of an electrical connector1800, mounted on an electrical component, showing the conductiveelements 1900 and the stair step nature 1901 of the rows of conductiveelements.

FIG. 20 illustrates the printed circuit board 2002 that mates withelectrical connector 1800. The closeup shows the rows of conductiveelements 2000 arrayed on the stair step surfaces 2001 of the printedcircuit board.

Alignment features insure that the electrical contact points on theconductive elements align with the electrical contact areas on themating part. For example, the alignment features may be a protrudingobject on a mating part that drops into a closely fitting cavity on theopposing mating part. The conductive elements may be aligned with manyother existing alignment methods.

FIG. 21 illustrates a closeup of a cross section of the electricalconnector 1800 as the electrical contact points of its conductiveelements 1900 begin to touch the electrical contact areas 2100 ofconductive elements 2000 on the printed circuit board 2002.

FIG. 22 shows a close-up of the electrical contacts of the conductiveelements 1900, 2000 when the electrical connector 1800 is completelymated to the printed circuit board 2002 and the conductive elements arecompletely flattened. FIG. 22 illustrates how the dimensions in theelectrical connector's stripline, which is a transmission line structure2201 can be made equivalent to the dimensions in the printed circuitboard's stripline 2202 especially if the relative dielectric constantsare kept the same or very similar within the electrical connector andthe printed circuit board. The groundplanes (denoted by the letter “G”)and signal conductive entities (denoted by the letter “S”) in theelectrical connector are parallel to the corresponding groundplanes andsignal conductive entities in the printed circuit board's stripline. Ahigh-speed, digital signal would see a stripline structure at theelectrical contact interface with very little of the physicaldiscontinuities that create signal integrity disruptions.

FIG. 23 illustrates how the conductors 2301 connecting the conductiveelements 2302 can have a shorter signal path 2303, 2304 in contrast tothe signal path illustrated in FIG. 21.

FIG. 24 illustrates an embodiment, a flexible circuit cable 2401 usingthe conductive elements 1900 arrayed in rows disposed on differentsurfaces of a flexible circuit with a stair step shape. The flexiblecircuit cable 2401 has a clamping plate 2402 to provide the contactforce and alignment features 2403, although there are many other methodsto create the latter functions.

FIG. 25 illustrates a multiple-branched flexible circuit cable 2500 ofthe flexible circuit cable type shown in FIG. 24. Two clamping plates2402 clamp conductive elements arrayed in rows that are disposed ondifferent surfaces of a flexible circuit having a stair step shape ateach of two branched ends. The branched ends fit into cavities 2501 inthe underlying backplane 2502. An additional cable end 2503interconnects with conductive elements arrayed in rows disposed ondifferent surfaces of a stair step shape in an IC package or otherelectronic device 2504.

FIG. 26 is an exploded assembly version of FIG. 25 showing themultiply-flexible circuit cable 2500 hovering over the backplane, thusillustrating the conductive elements arrayed on different surfaces ofstair step backplane cavities 2501 and on the stair step surface 2601 onthe IC package or other electronic device 2504.

FIG. 27 illustrates an embodiment wherein the printed circuit boards canbe disposed at 180 degrees or some other angle to each other and at anydistance from each other. The distance between the electricalconnector's conductors 4001 are maintained so that the signal integrityand impedance of the transmission line is uniform throughout theelectrical connector. The printed circuit board 2702 at the lower lefthas all the conductive elements 2703 at the printed circuit board's topsurface. The printed circuit board 704 on the lower right has a stairstep configuration wherein the rows of conductive elements 2705 are ondifferent stair step surfaces. FIG. 27 illustrates how signal integritydiscontinuities are kept to a minimum by eliminating capacitive stubscreated by a portion of the electrical contact, areas extending beyondthe electrical contact points.

FIG. 28 illustrates an embodiment wherein the conductive elements 2801in an electrical connector are attached to, or are an extension of aflexible circuit's conductive entities such as etched signal traces,wires in a cable or coaxial structures in a coaxial cable 2802. Theconductive elements 2801 arrayed on the electrical connector's stairstep surfaces mate with conductive elements 2803 arrayed on the stairstep surfaces of a printed circuit board 2804.

FIG. 29 illustrates an embodiment wherein the conductive elements 2801in the electrical connector are disposed so that the conductive elements2903 on the printed circuit boards 2901, 2902 may be parallel to andopposite each other.

FIG. 30 illustrates an embodiment, a two-part electrical connectorassembly having electrical connectors 3007, 3008 wherein, in eitherelectrical connector 3007, 3008, the electrical contact areas 3001 ofthe conductive elements 3002 are at an angle Ø 3003 with respect to thesurfaces of the electrical components such as printed circuit boards3004, 3005 rather than being parallel to them as previously shown. Theconductive elements 3002 are conductively attached to conductiveentities 3006 or signal traces in either of the electrical connectors3007 or 3008. As the electrical component, a daughter card 3004, whosemating direction is illustrated by the arrow, moves toward the otherelectrical component, a backplane 3005, the conductive elements 3002flatten against each other as they electrically mate. Although the angleØ 3003 at which the conductive elements 3002 come together is differentfrom the ones shown in FIGS. 5 through 29, the conductive elements 3002operate in the same manner.

There are numerous methods for manufacturing and bending the ends of thesprings into conductive elements. The rows of these conductive elementsmay be simultaneously etched from metal lead frames, stamped from stripsof metal foils or manufactured by many other methods. FIGS. 31 and 32show various methods whereby tooling is used to place a permanent curvein the conductive elements. The arrows indicate the direction of toolmovement. The anvils 3100, 3200 are placed on the pre-bent conductiveelements as static parts of the tooling, then the hammers 3101, 3201move as indicated by the arrows and permanently bend the conductiveelements as shown.

In another manufacturing and bending method, when the conductiveelements are in the flat, unbent shape, a laser can quickly heat the topsurface of the conductive elements creating a compressive stress in thetop layers of the conductive element. If an adhesive film or layeradheres the conductive element to the underlying substrate, then anetchant can dissolve the adhesive film and release the conductiveelement so it will curve upward away from the substrate.

In another manufacturing and bending method, a proprietary method calledLaser Peen® can be used to bend the conductive elements. The conductiveelement is painted with a black paint and the part submerged under awater curtain. A laser pulse passes through the water and strikes theblack paint vaporizing it. The vapor absorbs the laser light, whichproduces a rapidly expanding plasma plume. The expanding plasma isconfined between the surface of the conductive element and the watercurtain. The plasma creates a rapidly rising high-pressure shock wavethat travels into the material. The shock wave creates a peak stressthat yields and “cold works” the metal to plastically deform theconductive element at the surface. The compressive residual stressesthus formed in the top layer or surface of the metal curls theconductive element upward when the conductive element is released fromthe underlying substrate. The compressive residual stresses increase themetal's resistance to fatigue, fretting fatigue, and stress corrosioncracking.

Another manufacturing and bending method for the conductive elements isto use various electroplating or electro-coating methods. For instance,both tensile and compressive stresses can be produced while nickelplating. The stresses are induced by lowering temperature to or belowlow temperature (50-60 degrees C.), manipulating the PH of the platingbaths, using an organic material, or employing higher current densitythan usual. Nickel sulfamate baths will plate pure low-stressed finisheswithout using additives. Thus tensile layers can be plated on the metalsurface next to the underlying substrate and compressive layers platedor the top metal surface. A finishing gold plate will provide a lowelectrical contact resistance and corrosion-resistance.

Another manufacturing and bending method is to etch or stamp the shapeof the conductive elements out of metal or conductive material layers inprinted circuit board stock material or flexible circuit stock material.Although not limited to these manufacturing methods, the dielectric oradhesive material under the conductive element may be removed by variousmechanical removal methods such as grinding or machining, by chemicalremoval methods or by other methods not described here. The releasedconductive elements can be bent into shape by the various methodsdescribed in the previous paragraphs above.

FIG. 33 shows an alternate embodiment, an isometric view of anelectrical interconnection device, a post assembly 3300 wherein apivoting conductive element 3302 is encased in a groove 3303 in aninsulative mating post 3301. For illustrative purposes, the bent soldertail 3304 of the pivoting conductive element 3302 is shaped to allowsurface mount soldering to the solder pad of a printed circuit board.

FIG. 34 illustrates an isometric view of the pivoting conductive element3302 showing its curved nature with an electrical contact 3400 at itsright end. In FIG. 34, the electrical contact has a hemispherical shape,but may also be a conical shape, a sharp point or the like. The bentsolder tail 3304 can be surface mount soldered to the solder pad of aprinted circuit board. Alternatively, the tail can be a press fit typetail that is press fit into the plated through holes of a printedcircuit board or the tail may be any of several different types found inthe electrical connector industry. Alternatively, the bend solder tailcan be replaced by a conductive element 500 as shown in FIG. 5 that canmate with corresponding conductive elements on electrical components.

FIG. 35 illustrates the pivoting conductive element 3302, which has astraight region 3504 that is fixed within the material of the matingpost 3301 shown in FIG. 33. A pivot point 3503 corresponds to an edge(or corner) 3601 (shown in FIG. 36) on the mating post 3301. When aforce 3501 is applied downward on the curved portion of the pivotingconductive element 3302, it begins to flatten out because the fixedregion 3504 and the edge 3601 (shown in FIG. 36) act as reactivesupports. This causes the electrical contact 3400 to rise upward.

FIG. 36 is a sectioned view of the mating post 3301 showing the detailsof the groove 3303. The cutout 3600 provides room for the right end ofthe pivoting conductive element 3302 to move in an unimpeded fashion.The edge (or corner) 3601 is a pivot point 3503 on the pivotingconductive element 3302.

FIG. 37 is a sectioned view of the assembly in FIG. 33. The circled area3700, which corresponds to the straight region 3504 in FIG. 35,illustrates how the mating post 3301 captures the pivoting conductiveelement 3302. The cutout 3600 provides room for the right end of thepivoting conductive element 3302 allowing the top surface of theelectrical contact 3400 to reside below the bottom surface of groove3303.

In FIGS. 38A through 38C, the post assemblies 3300 have been sectionedto show how they electrically mate. FIG. 38A is a sectioned view of twopost assemblies 3300. A generally tubular housing (not shown here)encloses and guides the post assemblies 3300. The assemblies movetogether in the direction indicated by the arrows with an initialengagement length 3800. The electrical contacts 3400 are recessed insidethe cutouts 3600, which allow the electrical contacts 3400 to slide pasteach other as the post assemblies 3300 are mated together as shown inFIG. 38B.

In FIG. 38B, the post assemblies 3300 have moved closer together, withintermediate engagement length 3801, so that the electrical contacts3400 on each pivoting conductive element 3302 have moved past each otherand begun to touch the curved portion of the opposing pivotingconductive element 3302. The electrical contacts 3400 have moved beyond,the pivot point 3503. As the electrical contacts 3400 continue movingpast the pivot points 3503, the electrical contacts place force on theopposing pivoting conductive element 3302. Since the mating posts 3301constrain the pivoting conductive elements 3302, this action flattensthem producing the necessary contact force and low electrical contactresistance.

In FIG. 38C, the post assemblies 3300 are in the fully mated positionwith final engagement length 3802. The pivoting conductive element 3302is mated electrically and has been forced into a flat or nearly flatshape. Any portion of a pivoting conductive element 3302 projectingbeyond its electrical contact 3400 is negligible and does not act as acapacitive stub.

FIG. 39 illustrates electrical connectors 3901, 3902 composed of arraysof post assemblies 3904. The latter are similar to post assemblies 3300except that two pivoting conductive elements 3302, if desired, may beplaced side by side in each mating post to create a differential pair.Groundplanes 3903 separate rows of post assemblies 3904. Slots 3905 inthe groundplanes 3903 allow the groundplanes in the mating electricalconnectors to interleave with each other when the electrical connectorpair is mated. This provides isolation of any post assembly 3904 fromany other to reduce crosstalk between differential pairs or single endedconductors. Although FIG. 39 illustrates a mating electrical connectorpair that interconnects mezzanine or piggyback printed circuit boards,one of the post assemblies 3904 could be redesigned so that its pivotingconductive elements 3302 and its groundplanes 3903 are bent at 90degrees or some other angle. This would create an electrical connectorthat would interconnect printed circuit boards disposed at variousangles to each other. As an example, the angled electrical connector ona line card could plug into an electrical connector on a backplanewherein the line card and backplane are at varying angles with respectto each other.

FIG. 40 illustrates a side view of electrical connectors 3901 or 3902.Each post assembly 3904 has additional post assemblies behind the onesshown. These comprise a row of post assemblies attached to groundplanes3903. The rows are vertically staggered so that the surface mount tails4003 can be attached to solder pads on the stair step surfaces 4002 of aprinted circuit board 4001. Electrical connectors 3901 or 3902 could bedesigned so that end users or manufacturers of the rows of postassemblies 3904, or any type of post assembly mentioned herein, couldadjust the amount of their vertical staggering to match the verticaldistances of adjacent electrical contact rows on mating stair stepprinted circuit boards, stair step electrical components or the like.

FIG. 41 illustrates an embodiment of the electrical interconnectiondevice, a post assembly 4101 enclosing a conductive element (not shown),fully enclosed inside the insulative mating post 4103, and a postassembly 4102 having an inline conductive element 4104. A generallytubular housing (not shown here) encloses and guides the post assemblies4101, 4102.

FIG. 42 illustrates a sectioned view of the post assemblies 4101, 4102shown in FIG. 41. The conductive element 4205 is fixed with respect tothe mating post 4103 and straight or generally straight in the regionbetween its surface mount solder tail 4211 and the electrical contact atits other end. The post assembly 4102 has an inline conductive element4104 that is unsupported except in the fixed region 4206 as shown inFIG. 41. The inline conductive element 4104 is comprised of anattachment lead 4207, a curved leaf spring portion 4208, a straightportion 4209 bent downward at an angle to the leaf spring, and anelectrical contact 4210 at the end of the straight portion. Theattachment lead s 4207, 4211 may be replaced by surface mount solderleads, straight solder leads, press-fit leads or the like.Alternatively, the attachment leads 4207, 4211 can be replaced byconductive elements 500 as shown in FIG. 5 that mate with correspondingconductive elements on electrical components.

FIGS. 43A, 43B illustrate the how the post assemblies 4101, 4102 mateand electrically interconnect. FIG. 43A illustrates an inline conductiveelement 4104 inserted partially into post assembly 4101. The bottomsurface of the inline conductive element 4104 slides over corner 4301and inside mating post 4103, which lifts electrical contact 4210 overand past electrical contact 4302. FIG. 43B illustrates the fully matedpost assemblies 4101, 4102. As post assembly 4102 is partially insertedinto post assembly 4101, inline conductive element 4104 will slide underthe ramp surface 4303 inside mating post 4103. This action force iselectrical contact 4210 downward towards conductive element 4205. Aspost assembly 4102 is inserted farther into post assembly 4101, inlineconductive element 4104 slides along surface 4304 which fully forceselectrical contact 4210 onto the top surface of conductive element 4205.The foregoing action also causes the bottom surface of inline conductiveelement 4104 to be forced downward upon electrical contact 4302. Tworedundant electrical interconnections are generated and unwantedcapacitor stubs are eliminated.

An electrical connector containing an assembly of post assemblies 4101may electrically interconnect with an electrical connector containing acorrespondingly arranged assembly of post assemblies 4102 therebyelectrically interconnecting a plurality of electrical components. Postassemblies 4101, 4102 can replace post assemblies 3904 to create thesame electrical isolation as in electrical connectors 3901, 3902, whichare surrounded by groundplanes 3904 as shown in FIG. 39.

FIG. 44 illustrates an embodiment of an electrical interconnectiondevice 4400 comprised of a paralleled conductive element 4401, a signaltrace 4404 with electrical contact 4405 and a first dielectric layer4403 in an electrical component such as a printed circuit board. Signaltrace 4404 is fixed to the electrical component and is typically etchedfrom copper foil. The paralleled conductive element 4401 has anelectrical contact 4402 at its extreme end, a central portion with agenerally s-shaped or z-shaped curve and a straight portion 4406 at theother end fixed to a second dielectric layer (not shown to give a clearview of the paralleled conductive element 4401 that is part of anelectrical component such as an electrical connector.

FIG. 45A illustrates the electrical interconnection device 4400 in aside view as the electrical contacts 4402, 4405 begin to electricallymate. The paralleled conductive element 4401 has a straight portion 4406fixed to a second dielectric layer 4501, which was not shown in theprevious figure.

FIG. 45B illustrates the electrical interconnection device 4400 in aside view in the fully electrically mated condition. The seconddielectric layer 4501 has moved vertically toward the first dielectriclayer 4403. This movement creates contact forces at electrical contacts4402, 4405 that substantially flattens the paralleled conductive element4401 against signal trace 4404. The signal trace 4404 can be fabricatedusing conventional printed circuit board manufacturing methods. The endof the signal trace need not be curved upward away from the underlyingsubstrate nor does it require the attachment of a resilient, curved,conductive element.

FIG. 46 illustrates a sectioned view of an electrical interconnectiondevice 4600 wherein the paralleled conductive elements 4401 and/or thesignal traces 4404 are placed respectively into channels 4601 in thedielectric layer 4602 or into channels (not shown) in the dielectriclayer 4403. The paralleled conductive elements 4401 and the signaltraces 4404 are grouped together under the term “paralleled conductiveelement” or “paralleled conductive elements.” In FIG. 46, paralleledconductive element 4401-A is shown in the unmated condition. Paralleledconductive element 4401-B is shown as it would appear in the matedcondition. When the dielectric layers 4602, 4403 are brought together,the depth of the channels defines the amount of deflection of any matedparalleled conductive entities to within a desired range, which insuresthe correct range of electrical contact forces.

FIG. 47 illustrates an electrical interconnection device 4700 having astair step configuration. Paralleled conductive elements 4401 can bearrayed in rows on the stair step surfaces of the assembly 4701 thatelectrically mate with signal traces 4404 arrayed on corresponding rowson the stair step surfaces of the assembly 4702. The top dielectriclayer of assembly 4701 is cut away at section 4703 to show the fullcurvature of paralleled conductive element 4401. For clarity, assembly4701 has been flipped over 180 degrees as indicated by arrow 4704. Theadvantages of the embodiment are the elimination of unwanted parasiticcapacitances due to capacitive stubs and plated through holes, thecreation of two redundant electrical contact points per electricalsignal and less costly printed circuit board assemblies.

FIG. 48 illustrates another embodiment, an electrical bus connector 4800with multiple conductive elements 4801, periodically attached to aconductive beam, which is embedded inside the layers of a printedcircuit board 4804 and have the same properties as conductive elements500. The multiple electrical contact points at the ends of theconductive elements 4801 allow the same signal to be accessible atseveral places on the printed circuit board. The conductive elements4801 protrude through openings 4802, 4803 in the top layer 4805 of theprinted circuit board. Conductive elements 4801 can mate withcorresponding conductive elements on other electrical components orprinted circuit boards (not shown here).

FIG. 49 illustrates the electrical bus connector 4800 with the printedcircuit board layers exploded apart. The top conductive layer 4805 couldbe the top groundplane of a stripline transmission line structure. Thestripline's dielectric is air in this example. The conductive beam 4902,a straight length of conductive material with attached conductiveelements 4801 is the signal trace of the stripline, which resides in theslot 4905 in the PCB's middle layer 4903. The top conductive surface ofPCB layer 4904 is the lower groundplane for the stripline. The advantageof the embodiment is that the conductive beam 4902 is easily fabricatedand low cost. The electrical bus connector 4800 has multiple electricalcontacts at the ends of the conductive elements 4801 and each conductiveelement's geometry creates contact force. Each conductive element 4801has a corresponding conductive element on a mating part (not shown) suchas an electrical connector, printed circuit board, flexible circuit orelectrical component. The latter combination reduces the parasiticcapacitances in existing electrical connector buses.

The electrical bus connector's conductive beam 4902 with attachedconductive elements 4801 may alternatively be fabricated to turn atother angles, may drop down or may go up to other surfaces in amulti-layer electrical connector bus assembly. This property, which isthe capability for the electrical connector bus to move upward, downwardor sideways to other surfaces, facilitates the mating of conductiveelements 4801, which can reside on different stair step surfaces of theelectrical connector bus assembly. Conductive elements situated on otherprinted circuit boards, electronic components or other electricalconnectors with a stair step configuration can mate with the electricalconnector bus assembly having a corresponding stair step configuration.

FIG. 50 illustrates a section view of the electrical connector bus 4800in FIG. 48 showing the left side of the electrical bus connector signaltrace residing inside the cavity formed by the printed circuit boardlayers. The top surface 5001 of printed circuit board layer 4904 isconductive. If the vertical walls of the cavity above surface 4501 areconductively coated, then the electrical connector bus becomes awaveguide or coaxial-like transmission line.

FIG. 51 illustrates an electrical bus connector 5100 with ground andsignal transmission line structures embedded inside a multi-layerelectrical component. Conductive elements 5101, having the sameproperties as conductive elements 500, are integral with the topconductive layer 5103 that forms the top wall of the outer conductor ofthe coaxial transmission lines. The conductive elements 5102, having thesame properties as conductive elements 500, are at both ends of thecenter conductors. FIG. 52 illustrates the electrical bus connector 5100with top conductive layer 5103 removed. A coaxial transmission line iscomprised of the top conductive layer 5103, the conductively coatedvertical walls 5202 to the left and right of center conductor 5201 inthe cavity 5205 in the middle layer 5203, the bottom conductive layer5204 and the center conductor 5201. The center conductors 5201 aresupported by periodic, dielectric supports 5206 preferably having a low,dielectric constant, and low loss tangent such as but not limited tofoam blocks. The dielectric supports 5206 provide dimensional stabilityto the center conductors 5201 with respect to the outer conductorsdescribed above. The center and outer conductors of the coaxialtransmission lines may be straight, may be fabricated to turn at otherangles, and may drop down or go up to other coaxial transmission linestructures lying above; below or outside the coaxial structure shown inFIG. 51. This property facilitates the mating of conductive elements,which can reside on an electrical component's different stair stepsurfaces. Conductive elements (not shown here), situated on otherelectronic components with a stair step configuration can mate with theconductive elements 5101, 5102.

FIG. 53 illustrates an interposer conductor 5300 with two conductiveelements 5302, separated by a U-shaped portion causing the twoelectrical contacts 5301 to be aligned vertically above each other, foruse in an interposer connector. The spring would be captured in theinterposer connector by capturing the U-shaped portion of the spring.

FIG. 54 shows an embodiment of the interposer conductor in FIG. 53, theinterposer conductor 5400 wherein the two conductive elements 5401 aredisposed 180 degrees from each other about the joining bar 5402, for usein an interposer connector.

FIG. 55 illustrates an embodiment, an electrical interposer connector5500 using an array of interposer conductors 5300. FIG. 56 illustratesan exploded view of the electrical interposer connector 5500. Theinterposer conductors 5300 are captured by a capture plate 5601 and anarray plate 5602. An array of conductive elements 500 shown in FIG. 5,placed on electronic components such as printed circuit boards or thelike (not shown in the FIGS. 55, 56) can mate with the electricalinterposer connector 5500.

FIG. 57 illustrates the electrical interposer connector 5500 without thecapture plate 5601. The interposer conductors 5300 are shown in theirassembled positions. During assembly, each interposer conductor 5300 isinserted vertically into the opening 5701 and then moved to the leftover the clip flange 5702. The protrusions 5603 (shown in FIG. 56) onthe capture plate 5601 fit into all the openings 5701 in the array plate5602 thus fixing the interposer conductors 5300 with respect to thearray plate 5602. The parts of the electrical interposer connector 5500may be configured so that the interposer conductors are arrayed on stairstep surfaces of the electrical interposer connector 5500 toelectrically mate with corresponding conductive elements on stair stepsurfaces of electrical components.

FIG. 58 illustrates an embodiment, an electrical interposer connector5800 having interposer conductors 5300 used for signal transmission andconductive elements 5802 used for ground signals. The frame 5801 hasbeen sectioned to show the sides of three of the five signal ground barassemblies. One signal ground bar assembly 5810 is within the circledarea.

FIG. 59 illustrates the signal ground bar assembly 5810 composed of aninsulator 5901, interposer conductors 5300 and ground shield 5902 havingconductive elements 5802 that are attached to the top and bottom of theshielding groundplate 5903. The ground shield 5902 reduces crosstalkbetween interposer conductors 5300 and with suitable adjustments of theshapes, proximities and properties of parts within the signal ground barassembly 5810 improves the signal integrity of the interposer connector5800.

FIG. 60 illustrates an exploded view of the signal ground bar assembly5810 in FIG. 59. The interposer conductors 5300 are inserted into theinsulator 5901. Next, the ground shield 5902 is inserted into theinsulator 5901. The direction of insertion is illustrated by arrows6000. Instead of separate shielding groundplates 5903, the insulator5901 could be conductively coated in selected areas. Then the groundshield 5902 could be replaced by interposer conductors 5300 placed inintimate electrical contact with the conductive coatings. The groundedinterposer conductors 5300 would replace and/or augment the shieldinggroundplates with their conductive elements 5802.

The aforementioned embodiments of the electrical interposer connectormay electrically interconnect with printed circuit boards, electricalcomponents, or other electrical connectors, all of which may have theappropriate electrical contact areas or conductive elements 500 shown inFIG. 5.

FIG. 61 illustrates a sectioned view 6100 of the signal ground barassembly 5810 in FIG. 59. Half of an interposer conductor 5300 is shown.It illustrates how the ground shield 5902 with its grounded conductiveelements 5802 follows and can be at the proper distance away from theinterposer conductor 5300 to provide electromagnetic shielding and toimpart the geometry necessary to provide a uniformity of impedance thatimproves signal integrity.

FIG. 62 illustrates a sectioned view of a signal ground bar assembly6200, which is similar to all aforementioned signal ground barassemblies except for the addition of a conductive ground channel 6201inside the insulator 5901. The ground channel 6201 and the ground shield5902 are groundplanes. These two groundplanes 6201, 5902 and theinterposer conductors 5300 form stripline transmission lines, which canimprove signal integrity and lower crosstalk. The ground channel 6201may be conductively attached to ground shields: in: adjacent signalground bar assemblies. In addition or as an alternative, the groundchannel 6201 may be conductively attached at various locations to theground shield 5902.

FIG. 63 illustrates an embodiment, an electrical interposer connector6300 having stair step features indicated by the circled areas 6301. Theframe 6302 has been sectioned to show how the stair step features arecreated by making the height of a signal ground bar assembly greaterthan the one adjacent to it. The stair step rows of electrical contactson the interposer, conductors 5300 and conductive elements 5802 canelectrically mate with corresponding stair step rows of electricalcontacts on electrical components or other stair step electricalconnectors.

FIG. 64 illustrates an embodiment wherein a stair step electricalinterposer connector 6400, in top and bottom isometric views, that hastwo or more signal ground bar assemblies 5810, all being identical inshape, size and height. The signal ground bar assemblies 5810 aredisposed in a stair step arrangement 6401 by vertically offsetting anysignal ground bar assembly from the one adjacent to it.

FIG. 65 illustrates an embodiment of the conductive elements 500 shownin FIG. 5. When electrically mated, the conductive elements 6500, whichare oriented in the same manner as those in FIG. 5, may have one or moreelectrical contact points 6501 per conductive element 6500 to createthree or more electrical contacts for an electrical signal to passthrough. The geometry that creates this electrical contact redundancy,which increases electrical interconnection reliability, may bereplicated in all the other embodiments of the electricalinterconnection devices within this document.

Although the invention has been described with reference to specificexemplary embodiments thereof, it will be evident that variousmodifications and changes may be made thereto without departing from thebroader spirit and scope of the invention. The specification anddrawings are, accordingly, to be regarded in an illustrative rather thana restrictive sense.

1. An electrical interconnection assembly comprising: a first mountingstructure; a first conductive element having (i) fixed section and afirst curved resilient section, wherein fixed section is secured to themounting structure and the first curved resilient section is not securedto the mounting structure, (iii) a first tip formed at a distal end ofthe first curved resilient section, (iv) a landing zone disposed alongat least a portion of the first curved resilient section; a secondconductive element having a second tip and a second landing zone,wherein the second tip is in electrical contact with the first landingzone, and the first tip is in electrical contact with the second landingzone.
 2. The electrical interconnection device of claim 1 wherein thesecond tip comprises a protruding structure.
 3. The electricalinterconnection device of claim 1 wherein the second tip comprises aprotruding resilient structure.
 4. The electrical interconnection deviceof claim 1 wherein the second conductive element comprises a secondcurved resilient section that ends at the second tip.
 5. The electricalinterconnection device of claim 18 wherein the first conductive elementis configured such that, as a force is applied to the device, a distanceacross the electrically conductive closed loop decreases from a point onthe first conductive element to a point on the second conductiveelement, the first migrates along the second landing zone, creatingcontact wipe.
 6. The electrical interconnection device in claim 5,wherein the second conductive element is configured such that, as adistance across the electrically conductive closed loop decreases from apoint on the first conductive element to a point on the secondconductive element, the second tip migrates across the first landingzone, creating contact wipe.
 7. The electrical interconnection device ofclaim 1 further comprising at least one supporting structure that alignsthe first conductive element and the counterpart conductive element whenthey are moved together.
 8. The electrical interconnection device ofclaim 1 wherein the first conductive element is configured to mate withthe counterpart conductive element disposed on a surface configured as astair step for mating with other stair step structures.
 9. Theelectrical interconnection device of claim 1 further comprising at leastone structure for controlling a flexure of the first curved resilientsection of the first conductive element when the first conductiveelement is mated to the second conductive element.
 10. The electricalinterconnection device of claim 1 wherein the first conductive elementtapers to a point.
 11. The electrical interconnection device of claim 1wherein the mounting structure comprises at least one of a printedcircuit board, a substrate, a connector body, and an integrated circuitdevice.
 12. (canceled)
 13. (canceled)
 14. The electrical interconnectionof claim 12 further comprising at least one supporting structure thataligns the first and second conductive elements when they are movedrelative to one another.
 15. (canceled)
 16. An electricalinterconnection device comprising: mounting means; and a firstconductive element having a fixed section and at least one curvedresilient section extending outward from the fixed section, the fixedsection being secured to the mounting structure and wherein the firstconductive element further includes (i) means for contacting a landingzone of a counterpart conductive element, (ii) means, disposed along thelength of the first conductive element, for receiving a tip of thecounterpart conductive element, and (iii) a contact-free region disposedbetween the means for contacting the landing zone and the means forreceiving the tip.
 17. The electrical interconnection device of claim 1wherein a section of the first conductive element extending between thefirst tip to the second tip and a section of second conductive elementbetween the first tip to the second tip form an electrically conductiveclosed loop.
 18. The electrical interconnection device of claim 9wherein the at least one structure for controlling a flexure of thefirst curved resilient section of the first conductive element includesa portion of the first mounting structure extending beneath the firstcurved resilient section to at an area beneath the first tip.
 19. Theelectrical interconnection device of claim 18 wherein a flexure of thefirst curved resilient section of the first conductive element iscontrolled such that an increase of force upon the electricalinterconnection device progressively increases the contact area betweenthe first curved resilient section and the first mounting structure,beginning proximate a junction of the fixed section and the first curvedresilient section, and continuing to an area proximate the first tip.20. The electrical interconnection assembly of claim 1, the firstconductive element further comprising a second curved resilient sectionextending outward from the fixed section, the second curved resilientsection terminating in a third tip.
 21. The electrical interconnectionassembly of claim 20 wherein the fixed section is straight, such thatthe first curved resilient section and the second curved resilientsection extend outward from the fixed section in opposite directions.22. The electrical interconnection assembly of claim 20 wherein thefixed section is bent, such that the first curved resilient section andthe second curved resilient section extend outward from the fixedsection at an angle relative to each other.
 23. The electricalinterconnection assembly of claim 20 wherein the fixed section is bentat approximately 90 degrees, such that the first curved resilientsection and the second curved resilient section extend outward from thefixed section at an angle of approximately 90 degrees relative to eachother.
 24. The electrical interconnection assembly of claim 1 whereinthe first tip comprises a forked shape.
 25. The electricalinterconnection assembly of claim 1 wherein the first tip is disposed ona step surface of a stair step electrical contact assembly.
 26. A methodfor forming at least one electrical connection including a firstelectrical connection between a first conductive member and a secondconductive member, the first conductive member having a first curvedresilient section extending outward from a fixed member secured to afirst mounting structure, the first curved resilient section furtherhaving with a first end terminating in a first tip, the secondconductive member having second tip, the method comprising: engaging thefirst tip with the second conductive member; and engaging the second tipwith the first conductive member.
 27. The method of claim 26 furthercomprising: forming an electrically conductive closed loop that includesat least a portion of the first curved resilient section and at least aportion of the second conductive member.
 28. The method of claim 27further comprising: exerting a force on the first conductive member; andflexing at least a portion of the first curved resilient section. 29.The method of claim 28 further comprising wiping the first tip acrossthe second conductive member.
 30. The method of claim 28 furthercomprising reducing a distance across the electrically conductive closedloop.
 31. The method of claim 28 further comprising: progressivelyun-bowing the first curved resilient section; and engaging an un-bowedportion of the first curved resilient section against a physically rigidsurface.
 32. The method of claim 31 wherein engaging the un-bowedportion of the first curved resilient section begins proximate thesecond end secured to a first mounting structure and progresses towardthe first end.
 33. The method of claim 31 wherein engaging an un-bowedportion of the first curved resilient section against a physically rigidsurface comprises engaging an un-bowed portion of the first curvedresilient section against the first mounting structure.
 34. The methodof claim 26 wherein the second conductive member has a second curvedresilient section with a distal end terminating in the second tip and aproximal end secured to a second mounting structure.
 35. The methodaccording to claim 26 wherein the first conductive member further has asecond curved resilient section extending outward from the fixed member,the second curved resilient section having a third tip, such that acontinuous electrical path exists from the first tip to the third tipthrough the first conductive member, and wherein the at least oneelectrical connection further includes a second electrical connectionbetween a the first conductive member and a third conductive memberhaving a fourth tip, the method further comprising: engaging the fourthtip with the first conductive member; and engaging the third tip withthe third conductive member.